This paper sheds light on the internal structure and semantic properties of the phrasal compounds in Modern Greek. The crucial question is whether phrasal compounds form transparent syntactic structures or show symptoms of lexicalization. In order to check the empirical evidence, we conducted a speech production experiment and an experiment on the intuition of acceptability. Assuming that the second noun has predicative function, we address the question whether this noun in phrasal compounds shares the same functional properties with predicate nominals. In particular, we examine the possibility and the range of functions of pluralization of the predicative noun (N2). The crucial findings are that the availability of plural formation depends on lexical characteristics of the predicative noun and that the transparency in the functions of pluralization decreases in phrasal compounds. Based on this evidence, we claim that Modern Greek phrasal compounds undergo lexicalization with regard to the transparency of their semantic representations.